Optical amplifier, optical communication system, and optical amplification method

Abstract

Embodiments of the present application disclose an optical amplifier, an optical communication system, and an optical amplification method. The optical amplifier comprises an optical splitter, a detection unit, a control unit, a pump light source, and an optical amplification unit. The optical splitter is used for splitting incident signal light, a first path of split signal light is transmitted to the detection unit, and a second path of split optical signal is transmitted to the optical amplification unit. The detection unit is used for detecting the first path of signal light, the control unit is used for, on the basis of a detection result, controlling the power of pump light outputted by the pump light source, and the optical amplification unit is used for, on the basis of the pump light, amplifying the second path of signal light. If the detected result is less than a threshold, it indicates that an LoS state may occur, and the control unit is used for controlling the pump light source to keep the power of the pump light unchanged or to reduce the power of the pump light. This is equivalent to not turning off the pump light source even if the LoS state occurs. After the signal light is restored, the optical amplification unit can quickly restore normal operation, which is beneficial to improving working efficiency.

Description

Optical amplifier, optical communication system and optical amplification method

[0001] This application claims priority to the Chinese Patent Application No. 202411360321.2, filed on September 26, 2024, and entitled "Optical amplifier, optical communication system and optical amplification method", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of optical transmission, and in particular to an optical amplifier, an optical communication system and an optical amplification method. BACKGROUND

[0003] With the increase of the propagation distance of optical fiber communication, the loss of optical signals in optical fibers is increasing, and therefore, relay amplification is needed to regenerate the optical signals and ensure the quality of communication. An optical fiber amplifier is an optical amplifier device that directly amplifies optical signals in an optical fiber communication system. In a communication system using optical fibers, the optical signals are directly amplified without being converted into electrical signals. In a wavelength division multiplexing (WDM) system, the number of channels and the wavelength bands used at different times in different spans may vary according to the needs of communication, and the addition and removal of waves may occur. The addition and removal of waves not only causes a significant change in the optical power of the corresponding wavelength band, but also causes fluctuations in the optical power of other wavelength bands, thereby affecting the performance of the system.

[0004] Especially in the scenario of main and backup optical switch switching, when the main path fails, the backup path can be automatically switched to with less impact on the operation of the entire system. The switching of the optical switch has a fixed time. During the switching of the optical switch, the input end of the downstream optical amplifier will have a period of time during which the signal light is lost. In the conventional logic determination of the optical amplifier, the sudden loss of signal light will cause the optical amplifier to enter a loss of signal (LoS) state, in which the pump light is turned off to prevent the generation of amplified spontaneous emission (ASE) light. When the switching of the optical switch is completed, the signal light is restored, and the optical amplifier exits the LoS state, and the pump light is also restored. However, the process of turning off and restoring the pump light involves the process of recharging the gain medium in the optical amplifier, which causes the optical amplifier to take a long time to restore normal operation. SUMMARY

[0005] The embodiment of the present application provides an optical amplifier, an optical communication system and an optical amplification method. When the signal light appears in the LoS state, the pump light source is not immediately turned off. Thus, after the signal light is recovered, the optical amplification unit can quickly recover normal work, and work efficiency is improved.

[0006] In a first aspect, the embodiment of the present application provides an optical amplifier. The optical amplifier comprises a beam splitter, a detection unit, a control unit, a first pump light source and a first optical amplification unit. The beam splitter is configured to split the incident signal light, wherein the first path signal light after splitting is transmitted to the detection unit, and the second path signal light after splitting is transmitted to the optical amplification unit. The detection unit is configured to detect the first path signal light, and send the detection result to the control unit. The control unit is configured to control the power of the first pump light output by the first pump light source according to the detection result. The first optical amplification unit is configured to amplify the second path signal light according to the first pump light. If the detection result is less than a threshold value, the control unit is configured to control the first pump light source to keep the power of the first pump light unchanged or reduce the power of the first pump light.

[0007] In this embodiment, if the detection result is less than the threshold value, it indicates that the LoS state may appear. The control unit is configured to control the pump light source to keep the power of the pump light unchanged or reduce the power of the pump light. That is, even if the LoS state appears, the pump light source is not turned off. Thus, after the signal light is recovered, the optical amplification unit can quickly recover normal work, and work efficiency is improved.

[0008] In some possible embodiments, if the detection result is less than the threshold value all the time within a preset time length, the control unit is configured to control the first pump light source to stop outputting the first pump light. That is, if it is found according to the continuous detection result that the signal light is always in the LoS state, it indicates that the LoS of the signal light may be caused by the fault of the upstream signal light transmission link. At this time, it is reasonable to turn off the first pump light to avoid continuous generation of the ASE light.

[0009] In some possible implementation manners, if the control unit controls the first pump light source to reduce the power of the first pump light and the detection result returns to be greater than or equal to the threshold value, the control unit is configured to control the first pump light source to increase the power of the first pump light according to the detection result, so as to ensure that the signal light can be amplified normally after the signal light returns. In a possible scenario, if the detection result returns to be greater than or equal to the threshold value within a preset time length, it is equivalent to finding that the signal light is short of the LoS and then returns according to the continuous detection result, and it is indicated that the signal light is short of the LoS is caused by the master-backup path switching of the upstream signal light transmission link, and then the power of the first pump light should be restored. In another possible scenario, if the detection result is always less than the threshold value within a preset time length, it is indicated that the signal light transmission link may be faulty, the first pump light source has stopped outputting the first pump light, and then the detection result returns to be greater than or equal to the threshold value, and at this time, the first pump light should be restored to be output, which is equivalent to increasing the power of the first pump light.

[0010] In some possible implementation manners, the greater the increase amplitude of the detection result is, the greater the increase amplitude of the power of the first pump light is, so as to select the required pump light power according to the actual intensity of the signal light. For example, if the detection result returns to the result before the decrease, the control unit is configured to control the first pump light source to restore the power of the first pump light to the power before the decrease.

[0011] In some possible implementation manners, if the detection result returns to be greater than or equal to the threshold value, the control unit is configured to control the first pump light source to restore the power of the first pump light to the power before the decrease. That is to say, as long as the detection result returns to be greater than or equal to the threshold value, the power of the first pump light is completely restored to the power before the decrease, so as to improve the effect of amplifying the signal light as much as possible.

[0012] In some possible implementation manners, the optical amplifier further includes a second pump light source and a second optical amplification unit. The control unit is configured to control the second pump light source to output the power of the second pump light according to the detection result. The second optical amplification unit is configured to amplify the second path signal light passing through the first optical amplification unit according to the second pump light. If the detection result is less than the threshold value, the control unit is configured to control the second pump light source to stop outputting the second pump light or to reduce the power of the second pump light. In the architecture of the optical amplifier adopting the multi-stage optical amplification unit, if the control unit controls the first pump light source to keep the power of the first pump light unchanged or to reduce the power of the first pump light, the first optical amplification unit will generate ASE light, thereby affecting the downstream system. Therefore, the control unit can control the second pump light source to stop outputting the second pump light or to reduce the power of the second pump light, so that the ASE light generated by the first optical amplification unit is absorbed by the second optical amplification unit, thereby reducing the influence of the ASE light on the downstream system.

[0013] In some possible implementations, if the detection result is recovered to be greater than or equal to the threshold value, the control unit is configured to control the second pump light source to increase the power of the second pump light according to the detection result. If the control unit previously controls the second pump light source to stop outputting the second pump light, i.e., the output power of the second pump light is 0, and then the control unit controls the second pump light source to output the second pump light again, it is equivalent to increasing the power of the second pump light. That is, if the signal light has recovered to normal transmission, and the first optical amplification unit does not generate ASE light any more, the control unit controls the second pump light source to increase the power of the second pump light, so that the second optical amplification unit can normally amplify the signal light according to the second pump light. As an example, the greater the increase in the detection result, the greater the increase in the second pump power. For example, if the detection result is completely recovered to the result before the decrease, the control unit is configured to control the second pump light source to completely recover the power of the second pump light to the power before the decrease. As another example, as long as the detection result is recovered to be greater than or equal to the threshold value, the power of the second pump light is completely recovered to the power before the decrease.

[0014] In some possible implementations, the control unit is further configured to receive a message from the first communication link, and the message is configured to indicate the time of interruption of the signal light, so as to facilitate the control unit to know in advance that the signal light will have LoS.

[0015] In some possible implementations, the message is further configured to indicate the time of recovery of the signal light. If the detection result is less than the threshold value, and the control unit controls the first pump light source to decrease the power of the first pump light, the control unit is configured to control the first pump light source to increase the power of the first pump light before the time of recovery of the signal light, for example, the control unit can control the first pump light source to completely recover the power of the first pump light to the power before the decrease before the time of recovery of the signal light. It is equivalent to increasing the activity of the rare earth ions in the erbium fiber in advance before the signal light recovers, so as to improve the response speed of the erbium fiber to the changes of the signal light and the first pump light, and the first optical amplification unit can faster realize amplification of the signal light when the signal light truly recovers.

[0016] In some possible implementation manners, the optical amplifier further includes a second pump light source and a second optical amplification unit. The control unit is configured to control the second pump light source to output the power of the second pump light according to the detection result. The second optical amplification unit is configured to amplify the second signal light passing through the first optical amplification unit according to the second pump light. If the detection result is less than the threshold value, and the control unit controls the second pump light source to stop outputting the second pump light or to reduce the power of the second pump light, the control unit is configured to control the second pump light source to increase the power of the second pump light before the signal light is recovered, for example, the control unit can control the second pump light source to completely restore the power of the second pump light to the power before the decrease before the signal light is recovered. So that the second optical amplification unit can amplify the signal light faster when the signal light is truly recovered.

[0017] In some possible implementation manners, the control unit is further configured to receive a message from the first communication link, and the message is used to indicate the time when the signal light starts to be transmitted, so that the control unit controls the first pump light source to start to output the first pump light in advance before the time when the signal light starts to be transmitted. This is equivalent to increasing the activity of the rare earth ions in the erbium fiber in advance before the signal light arrives, thereby improving the response speed of the erbium fiber to the changes of the signal light and the first pump light, and the first optical amplification unit can amplify the signal light faster when the signal light truly arrives.

[0018] In some possible implementation manners, the control unit is further configured to receive a message from the first communication link, and the message is used to indicate the time when the power of the signal light changes, so that the control unit flexibly adjusts the power of the pump light emitted by the first pump light source according to the message. For example, the time when the power of the signal light increases or the time when the power of the signal light decreases. If the message is used to indicate the time when the power of the signal light increases, the control unit controls the first pump light source to increase the power of the first pump light at the time. If the message is used to indicate the time when the power of the signal light decreases, the control unit controls the first pump light source to decrease the power of the first pump light at the time.

[0019] In some possible implementation manners, the control unit is further configured to send a message through the second communication link, so that the downstream system can also timely perform corresponding processing according to the message.

[0020] In some possible implementation manners, the message adopts a Precision Time Protocol (PTP) format, which improves the realizability of the scheme.

[0021] In some possible implementation manners, the detection unit is specifically configured to detect the optical power of the first-path signal light; or, the detection unit is specifically configured to convert the first-path signal light into an electrical signal, and detect a voltage value of the electrical signal; or, the detection unit is specifically configured to convert the first-path signal light into an electrical signal, and detect a current value of the electrical signal.

[0022] In a second aspect, an embodiment of the present application provides an optical amplifier, which comprises a beam splitter, a detection unit, a control unit, a first pump light source and a first optical amplification unit. The beam splitter is configured to split signal light incident thereon, wherein first-path signal light after splitting is transmitted to the detection unit, and second-path signal light after splitting is transmitted to the optical amplification unit. The detection unit is configured to detect the first-path signal light, and send a detection result to the control unit. The control unit is configured to control the first pump light source to output power of first pump light according to the detection result. The first optical amplification unit is configured to amplify the second-path signal light according to the first pump light. If the detection result is less than a threshold value, the control unit is configured to control the first pump light source to keep the power of the first pump light unchanged in a part of time periods and reduce the power of the first pump light in another part of time periods.

[0023] In this embodiment, if the detection result is less than the threshold value, it indicates that the LoS state may occur, and the control unit is configured to control the first pump light source to change between keeping the power of the first pump light unchanged and reducing the power of the first pump light. That is, even if the LoS state occurs, the first pump light source is not turned off, so that the optical amplification unit can quickly recover to normal work after the signal light recovers, which is conducive to improving work efficiency. Moreover, controlling the first pump light source to change between keeping the power of the first pump light unchanged and reducing the power of the first pump light is also conducive to reducing failure rate of the first pump light source.

[0024] In a third aspect, an embodiment of the present application provides an optical amplifier, which comprises a control unit, a first pump light source and a first optical amplification unit. The first optical amplification unit is configured to amplify input signal light according to first pump light output by the first pump light source. The control unit is configured to receive a message from a first communication link, wherein the message is configured to indicate a time point of signal light interruption. The control unit is configured to control the first pump light source to keep the power of the first pump light unchanged or reduce the power of the first pump light from the time point of signal light interruption.

[0025] In this embodiment, if the control unit learns the time point of signal light interruption according to the message, the control unit is configured to control the pump light source to keep the power of the pump light unchanged or reduce the power of the pump light. That is, even if the LoS state occurs, the pump light source is not turned off, so that the optical amplification unit can quickly recover to normal work after the signal light recovers, which is conducive to improving work efficiency.

[0026] In some possible implementation manners, the message is used to indicate a time point of signal light recovery, and if the control unit controls the first pump light source to reduce the power of the first pump light from the time point of signal light interruption, the control unit is configured to control the first pump light source to increase the power of the first pump light before the time point of signal light recovery, for example, the control unit can control the first pump light source to completely restore the power of the first pump light to the power before the reduction before the time point of signal light recovery. That is, if the signal light is recovered after a short LoS, it is indicated that the LoS of the signal light is probably caused by the active-standby path switching of the upstream signal light transmission link, and the power of the first pump light should be restored to ensure that the signal light can be normally amplified after recovery.

[0027] In some possible implementation manners, the message is also used to indicate a duration of signal light interruption, and if the duration of signal light interruption is greater than a preset duration, the control unit is configured to control the first pump light source to stop outputting the first pump light. That is, if the signal light is continuously in the LoS state, it is indicated that the LoS of the signal light is probably caused by the failure of the upstream signal light transmission link, and the first pump light is closed at this time to avoid continuously generating ASE light.

[0028] In some possible implementation manners, the optical amplifier further includes a second pump light source and a second optical amplification unit. The second optical amplification unit is configured to amplify the signal light passing through the first optical amplification unit according to the second pump light output by the second pump light source. The control unit is configured to control the second pump light source to stop outputting the second pump light or reduce the power of the second pump light from the time point of signal light interruption. In the architecture of the optical amplifier adopting multiple-stage optical amplification units, if the control unit controls the first pump light source to keep the power of the first pump light unchanged or reduce the power of the first pump light, the first optical amplification unit generates ASE light, thereby affecting the downstream system. Therefore, the control unit can control the second pump light source to stop outputting the second pump light or reduce the power of the second pump light, so that the ASE light generated by the first optical amplification unit is absorbed by the second optical amplification unit, thereby reducing the influence of the ASE light on the downstream system.

[0029] In some possible implementation manners, the message is used to indicate a time point of signal light recovery, and the control unit is further configured to control the second pump light source to increase the power of the second pump light before the time point of signal light recovery, for example, the control unit can control the second pump light source to completely restore the power of the second pump light to the power before the reduction before the time point of signal light recovery. So that the second optical amplification unit can more quickly amplify the signal light when the signal light is truly recovered.

[0030] In some possible implementation manners, the message is further used to indicate a time point at which the signal light starts to be transmitted, so that the control unit controls the first pump light source to start to output the first pump light in advance before the time point at which the signal light starts to be transmitted. In other words, the activity of the rare earth ions in the erbium fiber can be improved in advance before the signal light arrives, so that the response speed of the erbium fiber to the signal light and the first pump light is improved, and the first optical amplification unit can amplify the signal light more quickly when the signal light really arrives.

[0031] In some possible implementation manners, the message is used to indicate a time point at which the power of the signal light changes, so that the control unit flexibly adjusts the power of the pump light emitted by the first pump light source according to the message. For example, the time point can be a time point at which the power of the signal light increases, or a time point at which the power of the signal light decreases. If the message is used to indicate the time point at which the power of the signal light increases, the control unit controls the first pump light source to increase the power of the first pump light at the time point. If the message is used to indicate the time point at which the power of the signal light decreases, the control unit controls the first pump light source to decrease the power of the first pump light at the time point.

[0032] In some possible implementation manners, the control unit is further configured to send the message through the second communication link, so that the downstream system can also timely perform corresponding processing according to the message.

[0033] In some possible implementation manners, the message adopts the PTP format, and the realizability of the scheme is improved.

[0034] In some possible implementation manners, the control unit is specifically configured to control the first pump light source to keep the power of the first pump light unchanged in a part of a time period and decrease the power of the first pump light in another part of the time period, starting from the time point at which the signal light is interrupted. In other words, the first pump light source changes between keeping the power of the first pump light unchanged and decreasing the power of the first pump light, which is beneficial to reducing the failure rate of the first pump light source.

[0035] In a fourth aspect, an embodiment of the present application provides an optical communication device, which comprises an optical transmitting unit, an optical receiving unit, and at least one optical amplifier as described in any of the embodiments of the first aspect to the third aspect. The at least one optical amplifier is configured to amplify signal light from the optical transmitting unit and then transmit the signal light, and / or the at least one optical amplifier is configured to amplify received signal light and then transmit the signal light to the optical receiving unit.

[0036] In a fifth aspect, an embodiment of the present application provides an optical communication system, which comprises at least one fiber interface unit (FIU) and at least one optical amplifier as described in any of the embodiments of the first aspect to the third aspect. The optical amplifier is configured to amplify signal light from the FIU. In some possible implementation manners, the message is further used to indicate a time point at which the signal light starts to be transmitted, so that the control unit controls the first pump light source to start to output the first pump light in advance before the time point at which the signal light starts to be transmitted. In other words, the activity of the rare earth ions in the erbium fiber can be improved in advance before the signal light arrives, so that the response speed of the erbium fiber to the signal light and the first pump light is improved, and the first optical amplification unit can amplify the signal light more quickly when the signal light really arrives.

[0031] In some possible implementation manners, the message is used to indicate a time point at which the power of the signal light changes, so that the control unit flexibly adjusts the power of the pump light emitted by the first pump light source according to the message. For example, the time point can be a time point at which the power of the signal light increases, or a time point at which the power of the signal light decreases. If the message is used to indicate the time point at which the power of the signal light increases, the control unit controls the first pump light source to increase the power of the first pump light at the time point. If the message is used to indicate the time point at which the power of the signal light decreases, the control unit controls the first pump light source to decrease the power of the first pump light at the time point.

[0032] In some possible implementation manners, the control unit is further configured to send the message through the second communication link, so that the downstream system can also timely perform corresponding processing according to the message.

[0033] In some possible implementation manners, the message adopts the PTP format, and the realizability of the scheme is improved.

[0034] In some possible implementation manners, the control unit is specifically configured to control the first pump light source to keep the power of the first pump light unchanged in a part of a time period and decrease the power of the first pump light in another part of the time period, starting from the time point at which the signal light is interrupted. In other words, the first pump light source changes between keeping the power of the first pump light unchanged and decreasing the power of the first pump light, which is beneficial to reducing the failure rate of the first pump light source.

[0035] In a fourth aspect, an embodiment of the present application provides an optical communication device, which comprises an optical transmitting unit, an optical receiving unit, and at least one optical amplifier as described in any of the embodiments of the first aspect to the third aspect. The at least one optical amplifier is configured to amplify signal light from the optical transmitting unit and then transmit the signal light, and / or the at least one optical amplifier is configured to amplify received signal light and then transmit the signal light to the optical receiving unit.

[0036] In a fifth aspect, an embodiment of the present application provides an optical communication system, which comprises at least one fiber interface unit (FIU) and at least one optical amplifier as described in any of the embodiments of the first aspect to the third aspect. The optical amplifier is configured to amplify signal light from the FIU.

[0037] In some possible implementation, the optical communication system further comprises a plurality of optical communication devices, and the at least one FIU is a wavelength division multiplexer. The wavelength division multiplexer is configured to combine the signal light from the plurality of optical communication devices. The optical amplifier is configured to amplify the combined signal light.

[0038] In some possible implementation, the optical communication system further comprises a controller. The controller is configured to communicate with the plurality of optical communication devices respectively, and the controller is further configured to send a message to the control unit of the optical amplifier.

[0039] In some possible implementation, the at least one FIU is a Wavelength Select Switch (WSS).

[0040] In a sixth aspect, an optical amplification method is provided. The optical amplification method is applied to an optical amplifier. The optical amplifier comprises a beam splitter, a detection unit, a control unit, a first pump light source and a first optical amplification unit. The method comprises: splitting, by the beam splitter, incident signal light, wherein a first path of the signal light after splitting is transmitted to the detection unit, and a second path of the signal light after splitting is transmitted to the optical amplification unit; detecting, by the detection unit, the first path of the signal light, and sending a detection result to the control unit; controlling, by the control unit, the first pump light source to output a power of the first pump light according to the detection result; and amplifying, by the first optical amplification unit, the second path of the signal light according to the first pump light. If the detection result is less than a threshold value, the control unit controls the first pump light source to keep the power of the first pump light unchanged or to reduce the power of the first pump light.

[0041] In some possible implementation, the method further comprises: if the detection result is always less than the threshold value within a preset time length, the control unit controls the first pump light source to stop outputting the first pump light.

[0042] In some possible implementation, the method further comprises: if the control unit controls the first pump light source to reduce the power of the first pump light, and the detection result recovers to be greater than or equal to the threshold value, the control unit controls the first pump light source to increase the power of the first pump light according to the detection result.

[0043] In some possible implementation, the greater the increase in the detection result, the greater the increase in the power of the first pump light.

[0044] In some possible implementation, if the detection result recovers to be greater than or equal to the threshold value, the control unit controls the first pump light source to increase the power of the first pump light according to the detection result comprises: the control unit controls the first pump light source to recover the power of the first pump light to the power before the decrease.

[0045] In some possible implementation, the optical amplifier further comprises a second pump light source and a second optical amplification unit. The method further comprises: controlling, by the control unit, the second pump light source to output the power of the second pump light according to the detection result; and amplifying, by the second optical amplification unit, the second path signal light passing through the first optical amplification unit according to the second pump light. If the detection result is less than the threshold value, the control unit is configured to control the second pump light source to stop outputting the second pump light or to reduce the power of the second pump light.

[0046] In some possible implementation, the method further comprises: if the detection result returns to be greater than or equal to the threshold value, controlling, by the control unit, the second pump light source to increase the power of the second pump light according to the detection result.

[0047] In some possible implementation, the method further comprises: receiving, by the control unit, a message from the first communication link, the message being configured to indicate the time point of the interruption of the signal light.

[0048] In some possible implementation, the message is further configured to indicate the time point of the resumption of the signal light. If the detection result is less than the threshold value and the control unit controls the first pump light source to reduce the power of the first pump light, the control unit is configured to control the first pump light source to increase the power of the first pump light before the time point of the resumption of the signal light.

[0049] In some possible implementation, the optical amplifier further comprises a second pump light source and a second optical amplification unit. The method further comprises: controlling, by the control unit, the second pump light source to output the power of the second pump light according to the detection result; and amplifying, by the second optical amplification unit, the second path signal light passing through the first optical amplification unit according to the second pump light. If the detection result is less than the threshold value, and the control unit controls the second pump light source to stop outputting the second pump light or to reduce the power of the second pump light, the control unit is configured to control the second pump light source to increase the power of the second pump light before the time point of the resumption of the signal light.

[0050] In some possible implementation, the method further comprises: receiving, by the control unit, a message from the first communication link, the message being configured to indicate the time point of the start of the transmission of the signal light.

[0051] In some possible implementation, the method further comprises: receiving, by the control unit, a message from the first communication link, the message being configured to indicate the time point of the change of the power of the signal light.

[0052] In some possible implementation, the method further comprises: sending, by the control unit, a message through the second communication link.

[0053] In some possible implementation, the message is in PTP format.

[0054] In some possible implementation manners, the detecting, by the detecting unit, the first-path signal light includes: detecting, by the detecting unit, an optical power of the first-path signal light; or, converting, by the detecting unit, the first-path signal light into an electrical signal, and detecting a voltage value of the electrical signal; or, converting, by the detecting unit, the first-path signal light into an electrical signal, and detecting a current value of the electrical signal.

[0055] In some possible implementation manners, if the detection result is less than the threshold value, the controlling, by the control unit, the first pump light source to keep the power of the first pump light unchanged or to reduce the power of the first pump light includes: if the detection result is less than the threshold value, controlling, by the control unit, the first pump light source to keep the power of the first pump light unchanged in a part of time periods and to reduce the power of the first pump light in another part of time periods.

[0056] In a seventh aspect, an embodiment of the present application provides an optical amplification method applied to an optical amplifier. The optical amplifier includes a beam splitter, a detecting unit, a control unit, a first pump light source, and a first optical amplification unit. The method includes: splitting, by the beam splitter, incident signal light, wherein a first-path signal light after splitting is transmitted to the detecting unit, and a second-path signal light after splitting is transmitted to the optical amplification unit; detecting, by the detecting unit, the first-path signal light, and sending a detection result to the control unit; controlling, by the control unit, the first pump light source to output a power of first pump light according to the detection result; and amplifying, by the first optical amplification unit, the second-path signal light according to the first pump light. If the detection result is less than a threshold value, the control unit controls the first pump light source to keep the power of the first pump light unchanged in a part of time periods and to reduce the power of the first pump light in another part of time periods.

[0057] In an eighth aspect, an embodiment of the present application provides an optical amplification method applied to an optical amplifier. The optical amplifier includes a control unit, a first pump light source, and a first optical amplification unit. The method includes: amplifying, by the first optical amplification unit, input signal light according to first pump light output by the first pump light source; receiving, by the control unit, a message from a first communication link, wherein the message is used to indicate a time of signal light interruption; and controlling, by the control unit, the first pump light source to keep the power of the first pump light unchanged or to reduce the power of the first pump light from the time of signal light interruption.

[0058] In some possible implementation manners, the message is used to indicate a time of signal light recovery. The method further includes: if the control unit controls the first pump light source to reduce the power of the first pump light from the time of signal light interruption, controlling, by the control unit, the first pump light source to increase the power of the first pump light before the time of signal light recovery.

[0059] In some possible implementation, the message is further used to indicate a duration of the interruption of the signal light. The method further includes: controlling, by the control unit, the first pump light source to stop outputting the first pump light if the duration of the interruption of the signal light is greater than a preset duration.

[0060] In some possible implementation, the optical amplifier further includes a second pump light source and a second optical amplification unit. The method further includes: amplifying, by the second optical amplification unit, the signal light passing through the first optical amplification unit according to second pump light output by the second pump light source; and controlling, by the control unit, the second pump light source to stop outputting the second pump light or to reduce the power of the second pump light starting from the time of the interruption of the signal light.

[0061] In some possible implementation, the message is used to indicate a time of resumption of the signal light. The method further includes: controlling, by the control unit, the second pump light source to increase the power of the second pump light before the time of the resumption of the signal light.

[0062] In some possible implementation, the message is further used to indicate a time of resumption of the signal light.

[0063] In some possible implementation, the message is used to indicate a time of resumption of the signal light.

[0064] In some possible implementation, the method further includes: controlling, by the control unit, the second pump light source to increase the power of the second pump light before the time of the resumption of the signal light.

[0065] In some possible implementation, the message is in a PTP format.

[0066] In some possible implementation, the controlling, by the control unit, the first pump light source to keep the power of the first pump light unchanged or to reduce the power of the first pump light starting from the time of the interruption of the signal light includes: controlling, by the control unit, the first pump light source to keep the power of the first pump light unchanged for a part of a time period and to reduce the power of the first pump light for another part of the time period.

[0067] In the embodiment of the present application, the optical amplifier comprises a light splitter, a detection unit, a control unit, a pump light source and an optical amplification unit. The light splitter is configured to split the incident signal light, and the first path signal light after splitting is transmitted to the detection unit, and the second path signal light after splitting is transmitted to the optical amplification unit. The detection unit is configured to detect the first path signal light, the control unit is configured to control the power of the pump light output by the pump light source according to the detection result, and the optical amplification unit is configured to amplify the second path signal light according to the pump light. Specifically, if the detection result is less than a threshold value, it means that the LoS state may occur, and the control unit is configured to control the pump light source to keep the power of the pump light unchanged or reduce the power of the pump light. In other words, even if the LoS state occurs, the pump light source is not turned off, so that after the signal light is recovered, the optical amplification unit can quickly recover normal work, which is beneficial to improve the work efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0068] FIG. 1 is a schematic diagram of an optical communication system;

[0069] FIG. 2 is a schematic diagram of an application scenario of an optical amplifier;

[0070] FIG. 3 is a schematic diagram of a structure of an optical amplifier in an embodiment of the present application;

[0071] FIG. 4 is a schematic diagram of another structure of an optical amplifier in an embodiment of the present application;

[0072] FIG. 5 is a schematic diagram of an embodiment of communication between an optical amplifier and an upstream system in an embodiment of the present application;

[0073] FIG. 6 is a schematic diagram of a format of a PTP message;

[0074] FIG. 7 is a schematic diagram of another structure of an optical amplifier in an embodiment of the present application;

[0075] FIG. 8 is a schematic diagram of another structure of an optical amplifier in an embodiment of the present application;

[0076] FIG. 9 is a schematic diagram of a structure of an optical communication device in an embodiment of the present application;

[0077] FIG. 10 is a schematic diagram of an embodiment of an optical amplification method provided in an embodiment of the present application;

[0078] FIG. 11 is a schematic diagram of another embodiment of an optical amplification method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0079] The embodiment of the present application provides an optical amplifier, an optical communication system and an optical amplification method. If the optical amplifier detects that a loss of signal (LoS) occurs, the pump light source keeps the power of the pump light unchanged or reduces the power of the pump light. In other words, even if the LoS state occurs, the pump light source will not be turned off immediately. In this way, after the signal light is recovered, the optical amplification unit can quickly recover normal work, and work efficiency is improved. The optical amplifier provided by the embodiment of the present application can be applied to long-distance optical communication, short-distance optical communication, data center optical interconnection and the like.

[0080] It should be noted that the terms "first", "second", and the like in the specification of the present application and claims and the above-described drawings are used to distinguish similar objects, and not to limit a specific order or sequence. It should be understood that the above terms can be interchanged under appropriate circumstances, so that the embodiments described in the present application can be implemented in an order other than that described in the present application. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to the process, method, product or device.

[0081] FIG. 1 is a schematic diagram of an optical communication system. As shown in FIG. 1, the optical communication system is specifically a wavelength division optical transmission system. A plurality of optical communication devices are respectively used to emit signal light of different wavelengths, and a wavelength division multiplexer is used to combine the signal light of different wavelengths and couple the combined signal light into an optical fiber for transmission. The transmission path of the signal light includes at least one optical amplifier and an optical cross unit. The optical amplifier is used to amplify the signal light, and the optical cross unit is used to realize cross interconnection of the signal light. The optical cross unit includes a wavelength selection switch (WSS), and the WSS and the wavelength division multiplexer can also be referred to as a fiber interface unit (FIU).

[0082] FIG. 2 is a schematic diagram of an application scenario of an optical amplifier. As shown in FIG. 2, the optical amplifier can be specifically applied to a fiber amplification scenario. A signal light source is used to output signal light, a pump light source is used to output pump light, a beam combiner is used to couple the signal light and the pump light to a gain medium, and the signal light is amplified by the gain medium. For example, the gain medium can be an erbium-doped fiber. For another example, the gain medium can also be an erbium-ytterbium co-doped fiber.

[0083] It should be noted that in the above wave division optical transmission system, according to the needs of communication, the number of channels and the wave band used at different time in different spans will be different, and the drop and add of waves will occur. The drop and add of waves will not only cause a significant change in the optical power of the corresponding wave band, but also cause fluctuations in the optical signal power of other wave bands, thereby affecting the performance of the system. Among them, the drop and add of waves can be divided into active drop and add of waves and passive fault drop and add of waves. The common scenarios of active drop and add of waves include wave channel expansion, network testing, wave channel switching, etc., which belong to the drop and add of waves scenarios that can be predicted in advance and are slow (seconds). The common scenarios of passive fault drop and add of waves include fiber fault scenarios such as line fiber breakage and in-station fiber breakage, and hardware fault scenarios such as optical amplifier board failure, optical switch failure, and subrack power failure. These scenarios cause a large number of drop and add of waves, and are fast (millisecond level).

[0084] In addition, there is a specific drop and add of wave scenario, that is, the master-slave optical switch switching. In order to improve the reliability of the system, many modules of the optical communication system will be backed up, that is, there are multiple lines of master-slave paths, and when the master path fails, the system can automatically switch to the backup path with less impact on the operation of the entire system. The switching here is completed by an optical switch, and the switching of the optical switch has a fixed time (for example, the switching time is 6 ms). Due to the slow switching of the optical switch, the system will still be affected to a certain extent. For example, during the optical switch switching process, the input end of the downstream optical amplifier will have a period of signal light loss, and in the normal logic judgment of the optical amplifier, the sudden loss of signal light will cause the optical amplifier to enter the LoS state, in which state the pump light will be turned off to prevent the generation of amplified spontaneous emission (ASE) light. When the optical switch switching is completed, the signal light is restored, and the optical amplifier is out of the LoS state, and the pump light is also restored. However, the process of turning off and restoring the pump light will involve the process of recharging the gain medium in the optical amplifier, which will cause the optical amplifier to take a long time to recover to normal work. Therefore, the embodiment of the present application provides an optical amplifier which will not immediately turn off the pump light source if the LoS state occurs. In this way, after the signal light is restored, the optical amplification unit can quickly recover to normal work, which is beneficial to improve the work efficiency. It should be understood that in addition to the above-mentioned master-slave optical switch switching scenario, other scenarios that may occur first drop and then add waves are also applicable to the embodiment of the present application. The optical amplifier provided by the embodiment of the present application will be described in detail below.

[0085] Figure 3 is a schematic diagram of a structure of an optical amplifier according to an embodiment of the present application. As shown in Figure 3, the optical amplifier 10 includes a light splitter 101, a detection unit 102, a control unit 103, a first pump light source 104, and a first optical amplification unit 105. Specifically, the optical amplifier 10 receives signal light from the upstream system 20, and the light splitter 101 splits the incident signal light, where a first path of the split signal light is transmitted to the detection unit 102, and a second path of the split signal light is transmitted to the optical amplification unit 105. It should be understood that the present application does not limit the specific splitting ratio of the light splitter 101, and generally needs to be such that most of the split signal light can be transmitted to the optical amplification unit 105. The detection unit 102 detects the first path of the signal light, and sends the detection result to the control unit 103. The control unit 103 controls the power of the first pump light output by the first pump light source 104 according to the detection result of the detection unit 102. The first optical amplification unit 105 amplifies the second path of the signal light according to the first pump light.

[0086] As an example, the detection unit 102 is specifically configured to detect the optical power of the first path of the signal light. For example, the detection unit 102 is a photoelectric diode (PD), and the detection unit 102 is configured to convert the first path of the signal light into an electrical signal, and detect the voltage value or the current value of the electrical signal. The control unit 103 can be specifically a processor, for example, can be a central processing unit (CPU), and can also be another general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or another programmable logic device, a transistor logic device, a hardware component, or any combination thereof. The general-purpose processor can be a microprocessor, or can be any conventional processor, and can also be a processing circuit implementing specific functions.

[0087] In one possible scenario, if the control unit 103 judges that the result detected by the detection unit 102 is less than the threshold value, it means that the signal light from the upstream system 20 has LoS, then the control unit 103 controls the first pump light source 104 to keep the power of the first pump light unchanged or reduce the power of the first pump light, instead of immediately turning off the first pump light. Among them, the first pump light source 104 keeping the power of the first pump light unchanged or reducing the power of the first pump light can have the following three scenarios. Scenario 1, if the result detected by the detection unit 102 is less than the threshold value, the control unit 103 controls the first pump light source 104 to keep the power of the first pump light unchanged. Scenario 2, if the result detected by the detection unit 102 is less than the threshold value, the control unit 103 controls the first pump light source 104 to reduce the power of the first pump light, for example, the power of the first pump light is reduced to a certain value and then no longer changes. Scenario 3, if the result detected by the detection unit 102 is less than the threshold value, the control unit 103 controls the first pump light source 104 to keep the power of the first pump light unchanged in a part of the period and reduce the power of the first pump light in another part of the period, that is, the first pump light source 104 changes between keeping the power of the first pump light unchanged and reducing the power of the first pump light, for example, this change can be periodic, that is, the power of the first pump light is first gradually reduced to a certain value and then gradually increased to the original power, so as to repeat this process to realize periodic change. It should be understood that compared with scenario 1, scenario 2 is beneficial to reduce the generated ASE light. Compared with scenario 1, scenario 3 is beneficial to reduce the failure rate of the first pump light source 104.

[0088] It should be noted that the purpose of the above operation is because the reason for the LoS of the signal light is not clear, which may be caused by the failure of the upstream signal light transmission link, or may be caused by the master-backup path switching of the upstream signal light transmission link. Therefore, if the result detected by the detection unit 102 is less than the threshold value, the first pump light is not immediately turned off, but the result continuously detected by the detection unit 102 is used to judge whether the LoS of the signal light is continuous or temporary.

[0089] For example, if the result detected by the detection unit 102 is less than the threshold value all the time within the preset time length, it indicates that the continuous LoS of the signal light is probably caused by the failure of the signal light transmission link upstream, and then the control unit 103 controls the first pump light source 104 to stop outputting the first pump light to avoid continuous generation of ASE light. After that, if the result detected by the detection unit 102 is greater than or equal to the threshold value again, the control unit 103 controls the first pump light source 104 to start outputting the first pump light again. For another example, if the result detected by the detection unit 102 is greater than or equal to the threshold value again within the preset time length, it indicates that the temporary LoS of the signal light is probably caused by the master-backup path switching of the signal light transmission link upstream, and if the power of the first pump light has been reduced by the first pump light source 104 before, the control unit 103 controls the first pump light source 104 to increase the power of the first pump light. The preset time length should be greater than the time length of the master-backup path switching, and the specific value is not limited here, for example, the time length of the master-backup path switching is 6 ms, and the preset time length can be set to 10 ms. It should be understood that the control unit 103 can control the first pump light source 104 to increase the power of the first pump light according to the latest detection result greater than or equal to the threshold value, and the greater the increase of the latest detection result, the greater the increase of the power of the first pump light. For example, if the optical power of the first path signal light is restored to 70% of the initial optical power, the power of the first pump light is increased to 70% of the power before the decrease; for another example, if the optical power of the first path signal light is restored to 70% of the initial optical power, the power of the first pump light is increased to 80% of the power before the decrease; for another example, if the optical power of the first path signal light is completely restored to the initial optical power, the power of the first pump light is completely restored to the power before the decrease.

[0090] It should be understood that the threshold value described above can be understood as a threshold value of the LoS of the signal light, in other words, if the result detected by the detection unit 102 is less than the threshold value, it can be considered that the signal light appears LoS. The threshold value is also related to the splitting ratio of the optical splitter 101, and the specific value is subject to the actual application, which is not limited here. For example, if the threshold value is expressed in the unit of optical power, the threshold value can be a certain value less than -10 dBm; for another example, if the threshold value is expressed in the unit of voltage or current, the threshold value can be a voltage value or a current value corresponding to a certain value less than -10 dBm. For the scenario that the power of the first pump light is reduced by the first pump light source 104, the application does not limit the specific decrease of the power, for example, the power of the first pump light can be reduced to at most 30% of the initial power.

[0091] It should be noted that the first optical amplification unit 105 can have various implementations. For example, the first optical amplification unit 105 can be implemented by using a gain medium such as an erbium-doped fiber or an erbium-ytterbium co-doped fiber to realize optical amplification. In this case, the optical amplifier 10 can also be referred to as a fiber amplifier. For another example, the first optical amplification unit 105 can be implemented by using a semiconductor optical amplifier (SOA) to realize optical amplification. In this case, the optical amplifier 10 can also be referred to as a semiconductor optical amplifier (SOA).

[0092] FIG. 4 is another schematic structural diagram of an optical amplifier according to an embodiment of the present application. In some possible implementation manners, the optical amplifier can also have a multi-stage optical amplification unit architecture. The specific number of optical amplification units depends on actual requirements and is not limited herein. FIG. 4 takes an example in which the optical amplifier further includes a second pump light source 106 and a second optical amplification unit 107. The second pump light source 106 outputs second pump light, and the second optical amplification unit 107 amplifies the signal light passing through the first optical amplification unit 105 according to the second pump light. For the multi-stage optical amplification unit architecture, if the detection result detected by the detection unit 102 is less than the threshold value (i.e., the signal light has LoS), the control unit 103 controls the first pump light source 104 to keep the power of the first pump light unchanged or to reduce the power of the first pump light. The first optical amplification unit 105 will generate ASE light, thereby affecting the downstream system 30. Therefore, the control unit 103 can control the second pump light source 106 to stop outputting the second pump light or to reduce the power of the second pump light, so that the ASE light generated by the first optical amplification unit 105 is absorbed by the second optical amplification unit 107, thereby reducing the influence of the ASE light on the downstream system 30. It should be understood that, compared with reducing the power of the second pump light, turning off the second pump light is more conducive to improving the effect of the second optical amplification unit 107 on the absorption of the ASE light. It should be understood that, if the optical amplifier further includes more stages of pump light sources and optical amplification units in addition to the second pump light source 106 and the second optical amplification unit 107, the control unit 103 can control at least one pump light source in the later stage to turn off the pump light or to reduce the power of the pump light. Correspondingly, if the detection result detected by the detection unit 102 within the preset time length returns to be greater than or equal to the threshold value, it indicates that the signal light has returned to normal transmission, and the first optical amplification unit 105 will not generate ASE light. Therefore, the control unit 103 controls the second pump light source 106 to increase the power of the second pump light, so that the second optical amplification unit 107 can normally amplify the signal light according to the second pump light. It should be understood that the control unit 103 can control the second pump light source 106 to increase the power of the second pump light according to the latest detection result that is greater than or equal to the threshold value. The greater the increase in the latest detection result, the greater the increase in the power of the second pump light.

[0093] It should be noted that the control unit 103 in the optical amplifier 10 can communicate with the upstream system 20 and the downstream system 30, which will be described in detail below.

[0094] FIG. 5 is a schematic diagram of an embodiment of the optical amplifier communicating with the upstream system according to an embodiment of the present application. As shown in FIG. 5, the upstream system includes a site and a wavelength division multiplexer, and the site includes a controller and a plurality of optical communication devices. The controller can communicate with the plurality of optical communication devices respectively, and the controller and the optical communication devices can communicate by transmitting electrical signals. For example, the controller can send instructions to the optical communication devices to control the working states of the optical communication devices; for another example, the optical communication devices can also send information to the controller to inform the controller of the working states of the optical communication devices. In addition, the controller can also send a light carrying a message to the control unit 103 of the optical amplifier through the wavelength division multiplexer, and the control unit 103 can control the pump light sources in the optical amplifier according to the received message. Specifically, as shown in FIG. 3, the optical amplifier further includes a splitting unit 108 and a combining unit 109. The splitting unit 108 is configured to split the input light by wavelength, and the splitting unit 108 transmits the light from the controller to the control unit 103 and transmits the signal light from the optical communication devices to the optical splitter 101. The combining unit 109 is configured to combine the light emitted by the control unit 103 and the signal light passing through the first optical amplification unit 105, and transmit the combined light to the downstream system 30.

[0095] In a possible scenario, the control unit 103 receives a message from the controller, which is used to indicate that the upstream signal light transmission link is to be switched from the main transmission link to the backup transmission link. Taking FIG. 5 as an example, the signal light transmitted by the optical communication device 1 and the optical communication device 2 has the same wavelength, the optical communication device 1 is located on the main transmission link, and the optical communication device 2 is located on the backup transmission link, and the controller can control the switching of the switch to use the main transmission link or the backup transmission link. That is, the controller knows in advance whether the optical transmission link will be switched, and can notify the control unit 103 of the optical amplifier of the message in advance. Then, if the control unit 103 determines that the result detected by the detection unit 102 is less than the threshold value, it can be directly determined that the reason for the LoS of the signal light is that the upstream signal light transmission link is switched from the main transmission link to the backup transmission link, which helps to determine the reason for the LoS of the signal light faster and reduces the misjudgment.

[0096] As an example, the message from the controller is also used to indicate the time instant of the signal light interruption and the time instant of the signal light restoration, i.e. the start time instant and the finish time instant of the master-backup path switching. On one hand, it is convenient for the control unit 103 to know in advance that the signal light will appear LoS. On the other hand, after the control unit 103 controls the first pump light source 104 to reduce the power of the first pump light, and before the time instant of the signal light restoration arrives, the control unit 103 controls the first pump light source 104 to increase the power of the first pump light in advance. Taking the example of the first optical amplification unit 105 employing an erbium-doped fiber, it is equivalent to increasing the activity of the rare earth ions in the erbium fiber in advance before the signal light restoration, so as to improve the response speed of the erbium fiber to the changes of the signal light and the first pump light, and the first optical amplification unit 105 can realize amplification of the signal light faster when the signal light is truly restored. It should be understood that the time length for the first pump light source 104 to increase the power of the first pump light in advance depends on actual requirements, for example, it can be in the order of 1 ms-1 s. Similarly, for the multi-stage optical amplification unit architecture shown in FIG. 4, after the control unit 103 controls the second pump light source 106 to stop outputting the second pump light or to reduce the power of the second pump light, and before the time instant of the signal light restoration arrives, the control unit 103 controls the second pump light source 106 to increase the power of the second pump light in advance, so that the second optical amplification unit 107 can realize amplification of the signal light faster when the signal light is truly restored.

[0097] In another possible scenario, before the optical amplifier 10 formally starts working, the control unit 103 receives a message from the controller, which is used to indicate the time instant of the signal light starting to be transmitted from the upstream system 20. Then, before the time instant of the signal light starting to be transmitted arrives, the control unit 103 controls the first pump light source 104 to start outputting the first pump light in advance. Taking the example of the first optical amplification unit 105 employing an erbium-doped fiber, it is equivalent to increasing the activity of the rare earth ions in the erbium fiber in advance before the signal light arrives, so as to improve the response speed of the erbium fiber to the changes of the signal light and the first pump light, and the first optical amplification unit 105 can realize amplification of the signal light faster when the signal light is truly transmitted. Similarly, for the multi-stage optical amplification unit architecture shown in FIG. 4, the control unit 103 controls the second pump light source 106 to start outputting the second pump light in advance, so that the second optical amplification unit 107 can realize amplification of the signal light faster when the signal light is truly transmitted.

[0098] In yet another possible scenario, the control unit 103 receives a message from the controller indicating the time at which the total power of the signal light from the upstream system 20 changes, for example, the time at which the total power of the signal light increases or the time at which the total power of the signal light decreases. It should be understood that the change in the total power of the signal light can be caused by the addition or removal of a light communication device in the station, or the change in the total power of the signal light can be caused by the change in the power of the signal light emitted by a light communication device in the station.

[0099] As an example, as shown in FIG. 5, initially only the light communication device 1 and the light communication device 3 are working in the station, and if the light communication device 4 is subsequently added to work, it is the scenario of adding a wave, at which time the total power of the signal light transmitted to the optical amplifier through the wavelength division multiplexer increases, the controller can send the time at which the wave is added to the control unit 103 of the optical amplifier, and the control unit 103 can control each pump light source to increase the power of the emitted pump light at the time. Conversely, if it is the scenario of removing a wave, the total power of the signal light transmitted to the optical amplifier through the wavelength division multiplexer decreases, the controller can send the time at which the wave is removed to the control unit 103 of the optical amplifier, and the control unit 103 can control each pump light source to decrease the power of the emitted pump light at the time.

[0100] As another example, as shown in FIG. 5, the light communication device 1, the light communication device 3, and the light communication device 4 are all working in the station, and if the light communication device 1 increases the optical power of the emitted signal light, at this time the total power of the signal light transmitted to the optical amplifier through the wavelength division multiplexer increases, the controller can send the time at which the total power of the signal light increases to the control unit 103 of the optical amplifier, and the control unit 103 can control each pump light source to increase the power of the emitted pump light at the time. Conversely, if the light communication device 1 decreases the optical power of the emitted signal light, at this time the total power of the signal light transmitted to the optical amplifier through the wavelength division multiplexer decreases, the controller can send the time at which the total power of the signal light decreases to the control unit 103 of the optical amplifier, and the control unit 103 can control each pump light source to decrease the power of the emitted pump light at the time.

[0101] It should be noted that after the control unit 103 receives the message from the upstream system 20 in each of the above scenarios, the control unit 103 can also forward the message to the downstream system 30, so that the downstream system 30 can also timely process according to the message. For example, the control unit 103 sends the light carrying the message to the combining unit 109, the combining unit 109 combines the light emitted by the control unit 103 and the signal light passing through the first optical amplification unit 105, and sends the combined light to the downstream system 30. The architecture of the downstream system 30 is similar to that of the upstream system 20, which will not be described here. For example, the downstream station also includes a controller, and the control unit 103 can forward the received message to the controller in the downstream station. It should be understood that the present application does not limit the format of the message from the upstream system 20, for example, the message can specifically adopt a precision time protocol (PTP) format. FIG. 6 is a schematic diagram of the format of a PTP message. As shown in FIG. 6, the PTP message includes a header, a body and a suffix, and the suffix can be specifically extended to carry the information indicated by the message.

[0102] It should be noted that in some possible scenarios, the control unit 103 in the optical amplifier can also not control the first pump light source 104 depending on the detection result of the detection unit 102, and the control unit 103 can directly control the first pump light source 104 according to the message from the upstream system 20. The following describes this implementation.

[0103] FIG. 7 is another schematic diagram of the structure of an optical amplifier in an embodiment of the present application. Unlike the structure of the optical amplifier shown in FIG. 3, as shown in FIG. 7, the optical amplifier can also not be provided with the optical splitter 101 and the detection unit 102. Specifically, the first optical amplification unit 105 amplifies the input signal light according to the first pump light output by the first pump light source 104. The control unit 103 is configured to receive the message sent by the upstream system 20. For example, the message is used to indicate the time when the signal light is interrupted, and the control unit 103 controls the first pump light source 104 to keep the power of the first pump light unchanged or reduce the power of the first pump light from the time when the signal light is interrupted. That is, even if the signal light appears LoS, the pump light is not immediately turned off.

[0104] In a first possible scenario, the message is also used to indicate the duration of the interruption of the signal light. If the duration of the interruption of the signal light is greater than a preset duration, it is indicated that the LoS of the signal light is likely caused by the failure of the upstream signal light transmission link, and the control unit 103 controls the first pump light source 104 to stop outputting the first pump light, so as to avoid continuous generation of ASE light.

[0105] In the second possible scenario, the message is also used to indicate the time instant of signal light recovery, which means that the LoS of signal light is probably caused by the master-backup path switching of the upstream signal light transmission link. After the control unit 103 controls the first pump light source 104 to reduce the power of the first pump light, and before the time instant of signal light recovery, the control unit 103 controls the first pump light source 104 to increase the power of the first pump light in advance.

[0106] In the third possible scenario, before the optical amplifier 10 formally starts to work, the control unit 103 receives a message from the upstream system 20, which is used to indicate the time instant of the start of signal light transmission from the upstream system. Then, before the time instant of the start of signal light transmission, the control unit 103 controls the first pump light source 104 to start to output the first pump light in advance.

[0107] In the fourth possible scenario, the message is also used to indicate the time instant of the change of the power of signal light, which can be the time instant of the increase of the power of signal light, or the time instant of the decrease of the power of signal light. If the message is used to indicate the time instant of the increase of the power of signal light, the control unit 103 controls the first pump light source 104 to increase the power of the first pump light at the time instant. If the message is used to indicate the time instant of the decrease of the power of signal light, the control unit 103 controls the first pump light source 104 to decrease the power of the first pump light at the time instant.

[0108] Fig. 8 is another structure of the optical amplifier according to an embodiment of the present application. For the scenario that the optical amplifier also adopts the architecture of multiple-stage optical amplification units, different from the structure of the optical amplifier shown in Fig. 4, as shown in Fig. 8, the optical amplifier can also not be provided with the optical splitter 101 and the detection unit 102. The second pump light source 106 outputs the second pump light, and the second optical amplification unit 107 amplifies the signal light according to the second pump light. If the control unit 103 controls the first pump light source 104 to keep the power of the first pump light unchanged or to reduce the power of the first pump light according to the received message, the first optical amplification unit 105 will generate ASE light, thereby affecting the downstream system 30. Therefore, the control unit 103 can control the second pump light source 106 to stop outputting the second pump light or to reduce the power of the second pump light from the time when the signal light is interrupted, so that the ASE light generated by the first optical amplification unit 105 is absorbed by the second optical amplification unit 107, thereby reducing the influence of the ASE light on the downstream system 30. Correspondingly, if the message is also used to indicate the time when the signal light is recovered, before the time when the signal light is recovered arrives, the control unit 103 controls the second pump light source 106 to increase the power of the second pump light in advance, so that the second optical amplification unit 107 can more quickly amplify the signal light when the signal light is truly recovered. If the message is also used to indicate the time when the signal light from the upstream system 20 starts to be transmitted, the control unit 103 controls the second pump light source 106 to start outputting the second pump light in advance, so that the second optical amplification unit 107 can more quickly amplify the signal light when the signal light truly arrives. If the message is also used to indicate the time when the power of the signal light changes, the control unit 103 controls the second pump light source 106 to increase the power of the second pump light at the time when the power of the signal light increases, or the control unit 103 controls the second pump light source 106 to reduce the power of the second pump light at the time when the power of the signal light decreases.

[0109] It should be noted that the optical amplifier provided by the embodiments of the present application can be integrated in an optical communication device, and the optical communication device can be specifically an optical module. Fig. 9 is a structure of an optical communication device according to an embodiment of the present application. As shown in Fig. 9, the optical communication device includes an optical transmitting unit, an optical receiving unit and at least one optical amplifier. As an example, the optical amplifier is arranged at an output port of the optical communication device, the optical transmitting unit is used to perform electro-optical conversion to obtain signal light, and the optical amplifier is used to amplify the signal light and then transmit the signal light to the output port. As another example, the optical amplifier is arranged at an input port of the optical communication device, the optical amplifier is used to amplify the signal light from the input port and then transmit the signal light to the optical receiving unit, and the optical receiving unit is used to perform optical-electric conversion on the signal light to obtain an electric signal.

[0110] The embodiment of the present application further provides an optical amplification method. The optical amplification method is applied to the optical amplifier described in the embodiments shown in FIG. 3 or FIG. 4. FIG. 10 is a schematic diagram of an embodiment of an optical amplification method provided by the embodiment of the present application. In the embodiment, the optical amplification method comprises the following steps.

[0111] 1-1, splitting the incident signal light by the optical splitter.

[0112] In the embodiment, the first-path signal light transmitted through the optical splitter is transmitted to the detection unit, and the second-path signal light transmitted through the optical splitter is transmitted to the optical amplification unit. It should be understood that the specific splitting ratio of the optical splitter is subject to the actual application scenario, and generally needs to make most of the signal light after splitting be transmitted to the optical amplification unit.

[0113] 1-2, detecting the first-path signal light by the detection unit.

[0114] In a possible implementation, the detection unit detects the first-path signal light in optical power. Taking the PD as an example, the PD converts the first-path signal light into an electrical signal, and detects the voltage value or the current value of the electrical signal.

[0115] 1-3, controlling the power of the first pump light output by the first pump light source according to the detection result by the control unit.

[0116] 1-4, amplifying the second-path signal light according to the first pump light by the first optical amplification unit.

[0117] Specifically, if the detection result is less than the threshold value, it indicates that the signal light appears LoS, and then the control unit controls the first pump light source to keep the power of the first pump light unchanged or reduce the power of the first pump light, instead of immediately turning off the first pump light. Whether the LoS of the signal light is continuous or temporary is determined according to the continuously detected result.

[0118] As an example, if the detection result is always less than the threshold value within a preset time length, it indicates that the LoS of the signal light is possibly caused by the fault of the upstream signal light transmission link, and then the control unit controls the first pump light source to stop outputting the first pump light, so as to avoid continuously generating ASE light. As another example, if the detection result is restored to be greater than or equal to the threshold value within a preset time length, it indicates that the LoS of the signal light is possibly caused by the active-standby path switching of the upstream signal light transmission link, and if the power of the first pump light has been reduced by the first pump light source, the control unit controls the first pump light source to increase the power of the first pump light.

[0119] In a possible scenario, for the optical amplifier adopting the architecture of multiple-stage optical amplification units as shown in FIG. 4, if the detection result is less than the threshold value, the second pump light source is controlled by the control unit to stop outputting the second pump light or to reduce the power of the second pump light, so that the ASE light generated by the front-stage optical amplification unit is absorbed by the rear-stage optical amplification unit, thereby reducing the influence of the ASE light on the downstream system. Correspondingly, if the detection result recovers to be greater than or equal to the threshold value within a preset time length, it is indicated that the signal light has recovered to normal transmission, and the front-stage optical amplification unit will not generate ASE light any more, and then the second pump light source is controlled by the control unit to increase the power of the second pump light, so that the rear-stage optical amplification unit can normally amplify the signal light according to the second pump light.

[0120] In a possible scenario, the control unit can also communicate with the upstream system and the downstream system, that is, the control unit can receive the message from the upstream system, and the control unit can also forward the message to the downstream system. As an example, the message received by the control unit is used to indicate the time of interruption of the signal light and the time of recovery of the signal light, that is, the starting time and the completion time of the master-slave path switching. Then, before the time of recovery of the signal light arrives, the control unit can control the first pump light source to increase the power of the first pump light in advance. As another example, the message received by the control unit is used to indicate the time of starting transmission of the signal light. Then, before the time of starting transmission of the signal light arrives, the control unit can control the first pump light source to start outputting the first pump light in advance. As an example, the message received by the control unit is used to indicate the time of change of the power of the signal light. If the message is used to indicate the time of increase of the power of the signal light, the control unit controls the first pump light source to increase the power of the first pump light at the time. If the message is used to indicate the time of decrease of the power of the signal light, the control unit controls the first pump light source to decrease the power of the first pump light at the time.

[0121] The embodiment of the present application further provides another optical amplification method. The optical amplification method is applied to the optical amplifier introduced in the embodiments shown in FIG. 7 or FIG. 8. FIG. 11 is a schematic diagram of an embodiment of another optical amplification method provided by the embodiment of the present application. In the embodiment, the optical amplification method comprises the following steps.

[0122] 2-1, receiving the message from the first communication link by the control unit.

[0123] The message is used to indicate the time of interruption of the signal light. On this basis, the message can also indicate the time of recovery of the signal light, or the message can also indicate the time length of interruption of the signal light, or the message can also indicate the time of starting transmission of the signal light.

[0124] 2-2, the control unit controls the first pump light source to keep the power of the first pump light unchanged or to reduce the power of the first pump light from the moment when the signal light is interrupted.

[0125] In a possible scenario, the message also indicates the moment when the signal light is recovered. After the control unit controls the first pump light source to reduce the power of the first pump light, and before the moment when the signal light is recovered, the control unit can also control the first pump light source to increase the power of the first pump light in advance.

[0126] In a possible scenario, the message also indicates the duration of the interruption of the signal light. If the duration of the interruption of the signal light is greater than a preset duration, the control unit can also control the first pump light source to stop outputting the first pump light.

[0127] In a possible scenario, the message also indicates the moment when the signal light starts to be transmitted before the optical amplifier formally starts to work. Before the moment when the signal light starts to be transmitted, the control unit can also control the first pump light source to start to output the first pump light in advance.

[0128] In a possible scenario, the message is also used to indicate the moment when the power of the signal light changes. If the message is used to indicate the moment when the power of the signal light increases, the control unit controls the first pump light source to increase the power of the first pump light at the moment. If the message is used to indicate the moment when the power of the signal light decreases, the control unit controls the first pump light source to decrease the power of the first pump light at the moment.

[0129] In a possible scenario, for the optical amplifier adopting the architecture of multiple-stage optical amplification units as shown in FIG. 7, the control unit can also control the second pump light source to stop outputting the second pump light or to reduce the power of the second pump light from the moment when the signal light is interrupted. Correspondingly, if the message also indicates the moment when the signal light is recovered, the control unit can also control the second pump light source to increase the power of the second pump light before the moment when the signal light is recovered. If the message also indicates the moment when the signal light starts to be transmitted from an upstream system, the control unit can also control the second pump light source to start to output the second pump light in advance. If the message is also used to indicate the moment when the power of the signal light changes, the control unit controls the second pump light source to increase the power of the second pump light at the moment when the power of the signal light increases, or the control unit controls the second pump light source to decrease the power of the second pump light at the moment when the power of the signal light decreases.

[0130] 2-3, the first optical amplification unit amplifies the input signal light according to the first pump light.

[0131] Specifically, the signal light from the upstream system is input into the first optical amplification unit, the first pump light source outputs the first pump light to the first optical amplification unit, and the first optical amplification unit amplifies the input signal light according to the first pump light.

[0132] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application. In the case of no conflict, the embodiments of the present application and the features in the embodiments can be combined with each other.

Claims

1. An optical amplifier, characterized in that, The optical amplifier comprises: a splitter, a detection unit, a control unit, a first pump light source and a first optical amplification unit; the splitter is configured to split the incident signal light, wherein the first path signal light after the splitting is transmitted to the detection unit, and the second path signal light after the splitting is transmitted to the optical amplification unit; the detection unit is configured to detect the first path signal light, and send the detection result to the control unit; the control unit is configured to control the first pump light source to output the power of the first pump light according to the detection result; the first optical amplification unit is configured to amplify the second path signal light according to the first pump light; if the detection result is less than a threshold value, the control unit is configured to control the first pump light source to keep the power of the first pump light unchanged or reduce the power of the first pump light.

2. The optical amplifier of claim 1, wherein, If the detection result is always less than the threshold value within a preset time length, the control unit is configured to control the first pump light source to stop outputting the first pump light.

3. The optical amplifier of claim 1, wherein, If the control unit controls the first pump light source to reduce the power of the first pump light, and the detection result returns to be greater than or equal to the threshold value, the control unit is configured to control the first pump light source to increase the power of the first pump light according to the detection result.

4. The optical amplifier of claim 3, wherein, The greater the increase of the detection result is, the greater the increase of the power of the first pump light is.

5. The optical amplifier of claim 3, wherein, If the detection result returns to be greater than or equal to the threshold value, the control unit is configured to control the first pump light source to restore the power of the first pump light to the power before the decrease.

6. The optical amplifier of claim 1, wherein, The optical amplifier further comprises a second pump light source and a second optical amplification unit; the control unit is configured to control the second pump light source to output the power of the second pump light according to the detection result; the second optical amplification unit is configured to amplify the second path signal light after the first optical amplification unit according to the second pump light; if the detection result is less than the threshold value, the control unit is configured to control the second pump light source to stop outputting the second pump light or reduce the power of the second pump light.

7. The optical amplifier of claim 6, wherein, If the detection result returns to be greater than or equal to the threshold value, the control unit is configured to control the second pump light source to increase the power of the second pump light according to the detection result.

8. The optical amplifier of any of claims 1 to 7, wherein, The control unit is further configured to receive a message from a first communication link, the message being used to indicate the time of interruption of the signal light.

9. The optical amplifier of claim 8, wherein, The message is further used to indicate the time of recovery of the signal light, if the detection result is less than the threshold value, and the control unit controls the first pump light source to reduce the power of the first pump light, the control unit is configured to control the first pump light source to increase the power of the first pump light before the time of recovery of the signal light.

10. The optical amplifier of claim 9, wherein, The optical amplifier further comprises a second pump light source and a second optical amplification unit; the control unit is configured to control the second pump light source to output the power of the second pump light according to the detection result; The second optical amplification unit is configured to amplify the second path signal light passing through the first optical amplification unit according to the second pump light. If the detection result is less than the threshold value, and the control unit controls the second pump light source to stop outputting the second pump light or to reduce the power of the second pump light, the control unit is configured to control the second pump light source to increase the power of the second pump light before the time point of the signal light recovery.

11. The optical amplifier of any of claims 1 to 7, wherein, The control unit is further configured to receive a message from the first communication link, the message being used to indicate the time point at which the signal light starts to transmit.

12. The optical amplifier of any of claims 1-7, wherein, The control unit is further configured to receive a message from the first communication link, the message being used to indicate the time point at which the power of the signal light changes.

13. The optical amplifier of any of claims 8 to 12, wherein, The control unit is further configured to send the message through the second communication link.

14. The optical amplifier of any of claims 8 to 13, wherein, The message adopts a Precision Time Protocol (PTP) format.

15. The optical amplifier of any of claims 1-14, wherein, The detection unit is specifically configured to detect the optical power of the first path signal light; or, the detection unit is specifically configured to convert the first path signal light into an electrical signal and detect the voltage value of the electrical signal; or, the detection unit is specifically configured to convert the first path signal light into an electrical signal and detect the current value of the electrical signal.

16. An optical communication device, comprising: The optical communication device comprises an optical transmitting unit, an optical receiving unit, and at least one optical amplifier as claimed in any one of claims 1 to 15; The at least one optical amplifier is configured to amplify the signal light from the optical transmitting unit before transmitting, and / or the at least one optical amplifier is configured to amplify the received signal light before transmitting to the optical receiving unit.

17. An optical communication system, characterized by Comprise: at least one Fiber Interface Unit (FIU) and at least one optical amplifier as claimed in any one of claims 1 to 15, the optical amplifier being configured to amplify the signal light from the FIU.

18. The optical communication system of claim 17, wherein, The optical communication system further comprises a plurality of optical communication devices, and the at least one FIU is a Wavelength Division Multiplexer (WDM); The WDM is configured to combine the signal light from the plurality of optical communication devices; The optical amplifier is configured to amplify the combined signal light.

19. The optical communication system of claim 18, wherein, The optical communication system further comprises a controller; The controller is configured to communicate with the plurality of optical communication devices respectively, and the controller is further configured to send a message to the control unit of the optical amplifier.

20. The optical communication system of any of claims 17-19, wherein, The at least one FIU is a Wavelength Selective Switch (WSS).

21. A method of optical amplification, comprising: The optical amplification method is applied to an optical amplifier, and the optical amplifier comprises a beam splitter, a detection unit, a control unit, a first pump light source, and a first optical amplification unit; the method comprises: splitting the incident signal light through the beam splitter, wherein the first path signal light passing through the splitting is transmitted to the detection unit, and the second path signal light passing through the splitting is transmitted to the optical amplification unit; detecting the first path signal light through the detection unit and sending the detection result to the control unit; controlling the first pump light source to output the power of the first pump light according to the detection result through the control unit; amplifying the second path signal light according to the first pump light through the first optical amplification unit; If the detection result is less than a threshold value, the control unit controls the first pump light source to keep the power of the first pump light unchanged or to reduce the power of the first pump light.

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